An army — massed ranks for war (Numbers 1:3, 'all who go out to the tsava'). The census is a military muster: everyone counted is a soldier. The same word makes the divine title 'Jehovah of ARMIES' (traditionally 'of hosts' — see the fuller discussion at tzeva'ot), and names the 'army of heaven' — sun, moon, and stars arrayed like troops. For the Levites the tsava is redefined: their 'service/warfare' is the tabernacle, not the battlefield (Numbers 4:23). → first discussed at Num 1:3